Two-cycle engine



March 3, 1931. J. B. HUMPERT 1,794,405

TWO-CYCLE ENGINE Filed'Dec. 15 1928 I N VEN TOR.

M5561: ab "#9 6 A TTORNEYS.

Fatented Eiders 3 E931:

JOEE B, HUMPEET, F SANFRANGIfiGQ, CALIEQRNIA.

awe-ovens ENGINE App1ication filed December 15, 1928.

This invention relates to internal combustion engines of the two-cycle type of any number of cylinders, and has for its objects a construction whereby compression of gases in the crank case is eliminated, the engine i extremely simple, all valves may be dispensed with, the usual wrist pin connection to the power piston is also eliminated, and hence piston slap is overcome, and all danger of a gases or gasoline vapor forcing its way past the piston into the crank oil is overcome.

Other advantages of the invention will appear in the following description and in the drawing accompanying the same.

Since the invention may be applied to engines having from one to any number of cylinders, and waether the same be arranged in a line, V-type, or radial type, the construction of one cylinder only is all that will. be necessary to show in the drawing.

Fig. 1 is a central vertical cross section of my engine taken through the cylinder and showing the arrangement of its piston and other parts.

Fig. 2 is a cross section of from the line 22 thereof.

Fig. 3 is a vertical central section of a cylinder similar to that shown in the upper portion. of Fig. 1, but with a modified arrangement of ports.

Briefly described my invention consists primarily in arranging two cylinders in endwise alignment with a division head between the c linders. The outer of the two cylinders is t e power cylinder in which the power plston reciprocates and against which the charge is fired in the usual manner, but the piston 1nstead of having a piston rod extending therefrom and connected to the crank of the engine, is provided with a rigid piston rod extending through a packing box into the second or inner cylinder, and in which second cylinder the piston rod connects to a cylindrical guide or cross-head in turn connected by a connecting rod to the crank shaft. The gases are compressed and fired in the outer cylinder and by means of the stuffing box all leakage to the inner cylinder is prevented and hence all tendencies to foul the oil within the crank case are entirely overcome.

Fig. 1 as seen Serial No. aaaaea.

In the drawings 1 is the inner cylinder, 2 the outer cylinder, 3 the water jacket around the outer cylinder and l the water space.

The inner cylinder is flanged at 5 and bolted directly to the crank case 6 within which is shown a portion 7 of the engine crank shaft. At the outer end of cylinder 1 is a flange 8 to which is bolted a flange 9 of the outer or power cylinder 2. Flange 8 extends across the outer end of cylinder 1 forming a head therefor which head is provided with a recess in the upper surface the sides of which are substantially in extension of the sides of the power cylinder and centrally of the headin the recessed portion is a stuffing box extending outwardly of the head through which extends a rod 10 rigidly secured to piston 11 reciprocably mounted in the power cylinder.

The lower or inner end of rod 10 is rigidly secured to a cylindrical guide or cross-head 12 which slides in the inner cylinder. This cross-head 12 preferably has spider arms at the upper end 13 and which are preferably permanently secured to the rod 10 as by welding at the point 14 or otherwise, and within the cross-head 12 is a wrist pin 15 mounting a connecting rod 16 engaging the crank on the crank shaft at its inner end as indicated.

The power piston 11 is of the usual type provided with rings as indicated, and it is desirable that the rod 10 be secured to the' piston in a manner so that it may be disconnected therefrom if desired, as in the manner shown in the drawings and wherein the upper end of the rod 10 is tightly threaded into a hub 17 projecting inwardly from the piston head and is prevented from rotation by a small key 18 in turn held in place by a nut 19 screwed to the end of the rod and countersunk into the piston head. The stuffing box for the rod 10 comprises a recess in head 8 with packing material 20 therein and surmounted by a compression spring 21 at its upper end bearing against the inside of a flange nut-22 screwed to an upwardly, projecting boss 23 on the head 8. This nut 22 is grooved around. its exterior or formed with a series of indentations into which a locking spring 24 is adapted to snap so as to hold the nut in adjusted position. The construction which might be confined under the piston in the position shown.

When in the down position a port 25in the wall at the lower end of the piston is aligned I over a port 26 in the side wall of the cylinder which communicates with a by-pass port 27 to a port 28 opening to the cylinder just above the upper end of the piston. The upper end of the piston is specially curved as indicated at 29 so as to deflect any gases entering port 28 in an upward direction as shown by the arrows, while the other side of the piston is reversely curved as at 30 so as to guide the gases to the exhaust port 31.

The head of cylinder 3 is preferably rounded or domed as indicated and with the spark plu centrally positioned as at 32.

TIre intake port for the gas is at 33, preferably formed in thehead- 8 of the inner cylinder and opening under the lower end of.

piston 11 when the same is at inner position. A carburetor of any suitable design is mounted over'the intake port 33 as indicated at 34 so as to supply the proper mixture of gasoline vapor and air upon upward movement or suction stroke of piston 11. In the construction shown it is necessary that a check valve be laced between the carburetor and the cylin er 2 so that upon downward stroke of the piston the gases will not be forced back into the carburetor. This valve may be located at any position along the port 33,0r preferably in a separate portion 35 of the strugture and wherein the valve is indicated at 3 In operation of this engine, upon outward stroke the gaseous mixture is drawn in the chamber under the piston 11, compressed upon the downward stroke simultaneously with the firing of the charge above it, and at the bottom of each stroke the compressed fresh gas rushes upward through the port 28 as soon as the same is uncovered by the top of the iston to aid in expellin the burnt gases by ollowing the course indicated by the arrows. The roportions of the parts being so made and t e position of the ports so determined that the rising piston will cut oil the discharge port 31 just before the fresh gas has had an opportunity to escape through the exhaust, thus completely scavenging the burnt gases each time in the well known way. By the arrangement described the crank bearings and walls of the inner c linder 1 may be lubricated by splash from t e crank case in the usual manner and this splash will also lubricate the rod 10.

Lubrication of the power piston however may be effected by any of the well-known forced feed construction or by placing a certain amount of lubricating oil in the gasoline as commonly done with sleeve valve engines.

It will be seen from the construction that there being no communication between the power cylinder and the lower or guide cylinder, none of the burnt gases or products of combustion can find their way into the crank case, but that the lubrication of the moving parts therein as well as the wrist pin 15 and walls of the cross-head will always be had from clean oil.

In the construction shown in Fig. 3 I am enabled to dispense with the check valve 36 shown in Fig. 1. This is accomplished by positioning the carburetor or intake for the I gases relatively high up on the cylinder'as indicated and where the intake port is designated 37.

All parts of the engine functioning in the same manner as described for Fig. 1 are given the same numerical designations so as to preserve identity therewith but the exhaust port 31 is shown at the left hand side of the cylinder so as not to confuse with the carburetor, and the by-pass ports 25 and 28 have been placed on the side where the carburetor is so as to keep the drawing clear.

In the construction shown in Fig. 3 the operation is substantially the same as that described for Fig. 1 except that on account of the elevation of the intake port 37 the inhaust cannot take place until the lower end of the piston has risen sufliciently to clear the intake port, and thereupon throu h a rarified condition under the piston the esh charge will be drawn under the piston, for compression upon the downward stroke, and subsequent ejection to the by-pass and port 28 to the upper part of the cylinder, while the burnt gases escape simultaneously as before described.

It will be manifest from the above description that various modificationsin detail construction may be resorted to not affecting the operation, and as may fall within the spirit of the invention and the scope of the appended claims.

I claim:

1. In an internal combustion engine having a power cylinder and a guide cylinder provided with outwardly extending flanges at one end each for bolting said cylinders together in alignment, a head in said guide cylinder adjacent its said flanged end, a piston reciprocable in the power cylinder provided with a piston rod extending through the head of the guide cylinder, a recess in the upper surface of said guidecylinder head formed in continuation of the inner sides of said power cylinder, a port extending from said recessed portion through the flange of said guide cylinder to the outer edge thereof and a perpendicularly extending flange formed on said outer edge around the opening of said intake port for bolting an intake valve device thereto.

2. In an internal combustion engine having a power cylinder and a guide cylinder of substantially the same diameter detachably secured together in alignment at one end each, a head in said guide cylinder integral therewith and positioned adjacent the end of said power cylinder, a piston reciprocable in the power cylinder provided with a piston rod extending through the head of said guide cylinder, a stufling box carried by the head on the upper side thereof effecting a sealed slidable joint between the rod and the head, said st'ufiing box removable from above the head when the power cylinder is removed.

JOHN B. HUMPERT. 

